The present invention concerns an attachment device for electrical equipment, such as an alternator/starter motor, in the clutch housing of an automobile.
Such devices are known according to which the electrical equipment is attached in the clutch housing situated between the gearbox and crankcase of the vehicle, the electrical equipment comprising a fixed stator as integral part of the clutch housing and a rotor integral with the engine crankshaft.
This known solution has the major shortcoming of requiring a relatively large air gap between the rotor and stator of about 0.8 mm because of the ovoid movements of the rotor in unison with the crankshaft and problems of expansion of the clutch housing, made of aluminum, during operation of the electrical equipment.
The invention proposes a device that permits a reduction in the air gap to a specified value and elimination of the problems of expansion of the clutch housing.
For this purpose, according to the invention, the attachment device for electrical equipment, such as an alternator/starter motor, in the clutch housing of an automobile and situated between the gearbox and crankcase of the vehicle, comprises a stator fixed relative to the clutch housing and a rotor that can be rotated by the crankshaft of the engine, where in the assembly comprising the stator, rotor and a support hub of the rotor mounted on a bearing, such as a ball bearing, is housed in an independent housing integral with the clutch housing and at a spacing therefrom.
Preferably, the aforementioned assembly is pre-assembled in the independent housing before attachment of this housing to the clutch housing.
The bearing of the rotor support hub is mounted on a cylindrical central part of the independent housing coaxially surrounding the connection shaft between the crankshaft and the input shaft of the gearbox.
The rotor support hub is connected by rotary coupling means to a cover of the housing integral with the flywheel of the engine.
According to a first variant, the coupling means comprises a collar of elastomeric material, such as silicone, having on one side axially protruding and peripherally spaced hollow prismatic elements with a rectangular base, which are mounted respectively in matching cavities of the rotor support hub and a rigid metal collar having on one side axially protruding and peripherally spaced prismatic elements with rectangular bases that are mounted respectively in the hollow prismatic elements of the elastomeric collar, the metal collar being integral on its side opposite the housing cover.
According to a second variant, the coupling means comprises blocks of elastomeric material, such as silicone, respectively mounted in the circumferentially spaced matching cavities of the rotor support hub, and cogs or pins integral on one side of the housing cover, parallel to the axis of rotation of the rotor and spaced circumferentially, where the cogs or pins engage holes made in the elastomer blocks.
Preferably, the independent housing comprises a lateral wall perpendicular to the crankshaft connected to the cylindrical central part by an oblique wall and a circular wall extending perpendicular to the lateral wall so as to define the seat in which the aforementioned assembly is mounted by its introduction from the open side of the housing opposite the lateral wall, the circular wall enclosing the stator of the electrical equipment on one part.
Advantageously, a circuit is provided to cool the electrical equipment.
Preferably, the cooling circuits consist of an annular band comprising a sealed annular chamber in which a cooling liquid can circulate, such as a mixture of water and antifreeze, and this annular band is arranged on a circular external peripheral surface of the stator, is interposed between the circular wall of the housing and an annular attachment clamp of the stator in the housing, and is held between these two parts by external connecting rods, one of the ends of the annular band being integral with one connecting rod and its other mobile end being connected to the connecting rod by a spring.
The annular band is attached to the independent housing by the external connecting rods, parallel to the circular wall of the housing, anchored on one side to the housing and traversing on the other side an annular mounting clamp of the stator in the housing and being supported and clamped on the circular edge of the annular band opposite the circular edge of the circular wall of the housing.
The cooling circuit also comprises two external supply and discharge tubes for cooling liquid in the annular chamber that are connected in terms of fluid communication to the annular band.
The device also comprises a sleeve fixed in the cylindrical central part of the independent housing and permits guiding of a disengagement stop in translation.
According to one variant, the rotor support hub is made from a single piece of aluminum. According to another variant, the rotor support hub comprises two flanges made of sheet metal attached to each other by crimping.